From: Michal Hocko <mhocko@kernel.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>,
Robin Murphy <robin.murphy@arm.com>,
Matthew Wilcox <willy@infradead.org>,
Christopher Lameter <cl@linux.com>,
Levin Alexander <Alexander.Levin@microsoft.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Nicolas Boichat <drinkcat@chromium.org>,
Huaisheng Ye <yehs1@lenovo.com>, Tomasz Figa <tfiga@google.com>,
Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org, Pekka Enberg <penberg@kernel.org>,
linux-mm@kvack.org, iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org,
David Rientjes <rientjes@google.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
yingjoe.chen@mediatek.com, Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Mel Gorman <mgorman@techsingularity.net>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v2 0/3] iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables
Date: Fri, 23 Nov 2018 13:30:40 +0100 [thread overview]
Message-ID: <20181123123040.GH8625@dhcp22.suse.cz> (raw)
In-Reply-To: <555dd63a-0634-6a39-7abc-121e02273cb2@suse.cz>
On Fri 23-11-18 13:23:41, Vlastimil Babka wrote:
> On 11/22/18 9:23 AM, Christoph Hellwig wrote:
[...]
> > But I do agree with the sentiment of not wanting to spread GFP_DMA32
> > futher into the slab allocator.
>
> I don't see a problem with GFP_DMA32 for custom caches. Generic
> kmalloc() would be worse, since it would have to create a new array of
> kmalloc caches. But that's already ruled out due to the alignment.
Yes that makes quite a lot of sense to me. We do not really need a
generic support. Just make sure that if somebody creates a GFP_DMA32
restricted cache then allow allocating restricted memory from that.
Is there any fundamental reason that this wouldn't be possible?
--
Michal Hocko
SUSE Labs
WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>,
Robin Murphy <robin.murphy@arm.com>,
Matthew Wilcox <willy@infradead.org>,
Christopher Lameter <cl@linux.com>,
Levin Alexander <Alexander.Levin@microsoft.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Nicolas Boichat <drinkcat@chromium.org>,
Huaisheng Ye <yehs1@lenovo.com>, Tomasz Figa <tfiga@google.com>,
Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org, Pekka Enberg <penberg@kernel.org>,
linux-mm@kvack.org, iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org,
David Rientjes <rientjes@google.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
yingjoe.chen@mediatek.com, Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Mel Gorman <mgorman@techsingularity.net>,
Andrew Morton <akpm@linux-foundati>
Subject: Re: [PATCH v2 0/3] iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables
Date: Fri, 23 Nov 2018 13:30:40 +0100 [thread overview]
Message-ID: <20181123123040.GH8625@dhcp22.suse.cz> (raw)
In-Reply-To: <555dd63a-0634-6a39-7abc-121e02273cb2@suse.cz>
On Fri 23-11-18 13:23:41, Vlastimil Babka wrote:
> On 11/22/18 9:23 AM, Christoph Hellwig wrote:
[...]
> > But I do agree with the sentiment of not wanting to spread GFP_DMA32
> > futher into the slab allocator.
>
> I don't see a problem with GFP_DMA32 for custom caches. Generic
> kmalloc() would be worse, since it would have to create a new array of
> kmalloc caches. But that's already ruled out due to the alignment.
Yes that makes quite a lot of sense to me. We do not really need a
generic support. Just make sure that if somebody creates a GFP_DMA32
restricted cache then allow allocating restricted memory from that.
Is there any fundamental reason that this wouldn't be possible?
--
Michal Hocko
SUSE Labs
WARNING: multiple messages have this Message-ID (diff)
From: mhocko@kernel.org (Michal Hocko)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 0/3] iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables
Date: Fri, 23 Nov 2018 13:30:40 +0100 [thread overview]
Message-ID: <20181123123040.GH8625@dhcp22.suse.cz> (raw)
In-Reply-To: <555dd63a-0634-6a39-7abc-121e02273cb2@suse.cz>
On Fri 23-11-18 13:23:41, Vlastimil Babka wrote:
> On 11/22/18 9:23 AM, Christoph Hellwig wrote:
[...]
> > But I do agree with the sentiment of not wanting to spread GFP_DMA32
> > futher into the slab allocator.
>
> I don't see a problem with GFP_DMA32 for custom caches. Generic
> kmalloc() would be worse, since it would have to create a new array of
> kmalloc caches. But that's already ruled out due to the alignment.
Yes that makes quite a lot of sense to me. We do not really need a
generic support. Just make sure that if somebody creates a GFP_DMA32
restricted cache then allow allocating restricted memory from that.
Is there any fundamental reason that this wouldn't be possible?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-11-23 12:30 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-11 9:03 [PATCH v2 0/3] iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables Nicolas Boichat
2018-11-11 9:03 ` Nicolas Boichat
2018-11-11 9:03 ` Nicolas Boichat
2018-11-11 9:03 ` [PATCH v2 1/3] mm: slab/slub: Add check_slab_flags function to check for valid flags Nicolas Boichat
2018-11-11 9:03 ` Nicolas Boichat
2018-11-11 9:03 ` Nicolas Boichat
2018-11-11 9:03 ` [PATCH v2 2/3] mm: Add support for SLAB_CACHE_DMA32 Nicolas Boichat
2018-11-11 9:03 ` Nicolas Boichat
2018-11-11 9:03 ` Nicolas Boichat
2018-11-21 18:32 ` Christopher Lameter
2018-11-21 18:32 ` Christopher Lameter
2018-11-22 0:52 ` Nicolas Boichat
2018-11-22 0:52 ` Nicolas Boichat
2018-11-22 0:52 ` Nicolas Boichat
2018-11-11 9:03 ` [PATCH v2 3/3] iommu/io-pgtable-arm-v7s: Request DMA32 memory, and improve debugging Nicolas Boichat
2018-11-11 9:03 ` Nicolas Boichat
2018-11-11 9:03 ` Nicolas Boichat
2018-11-21 16:46 ` Will Deacon
2018-11-21 16:46 ` Will Deacon
2018-11-21 17:38 ` Christopher Lameter
2018-11-21 17:38 ` Christopher Lameter
2018-11-21 17:43 ` Robin Murphy
2018-11-21 17:43 ` Robin Murphy
2018-11-21 18:18 ` Christopher Lameter
2018-11-21 18:18 ` Christopher Lameter
2018-11-21 18:02 ` Michal Hocko
2018-11-21 18:02 ` Michal Hocko
2018-11-22 1:20 ` Nicolas Boichat
2018-11-22 1:20 ` Nicolas Boichat
2018-11-22 1:20 ` Nicolas Boichat
2018-11-23 12:15 ` Vlastimil Babka
2018-11-23 12:15 ` Vlastimil Babka
2018-11-21 18:20 ` [PATCH v2 0/3] iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables Christopher Lameter
2018-11-21 18:20 ` Christopher Lameter
2018-11-21 21:38 ` Matthew Wilcox
2018-11-21 21:38 ` Matthew Wilcox
2018-11-21 21:38 ` Matthew Wilcox
2018-11-21 22:26 ` Robin Murphy
2018-11-21 22:26 ` Robin Murphy
2018-11-21 22:26 ` Robin Murphy
2018-11-22 1:05 ` Nicolas Boichat
2018-11-22 1:05 ` Nicolas Boichat
2018-11-22 1:05 ` Nicolas Boichat
2018-11-22 2:35 ` Matthew Wilcox
2018-11-22 2:35 ` Matthew Wilcox
2018-11-22 2:35 ` Matthew Wilcox
2018-11-22 5:56 ` Nicolas Boichat
2018-11-22 5:56 ` Nicolas Boichat
2018-11-22 5:56 ` Nicolas Boichat
2018-11-22 8:26 ` Christoph Hellwig
2018-11-22 8:26 ` Christoph Hellwig
2018-11-22 8:26 ` Christoph Hellwig
2018-11-22 15:16 ` Matthew Wilcox
2018-11-22 15:16 ` Matthew Wilcox
2018-11-22 15:16 ` Matthew Wilcox
2018-11-22 15:19 ` Christoph Hellwig
2018-11-22 15:19 ` Christoph Hellwig
2018-11-22 15:19 ` Christoph Hellwig
2018-11-22 8:23 ` Christoph Hellwig
2018-11-22 8:23 ` Christoph Hellwig
2018-11-22 8:23 ` Christoph Hellwig
2018-11-23 3:04 ` Nicolas Boichat
2018-11-23 3:04 ` Nicolas Boichat
2018-11-23 3:04 ` Nicolas Boichat
2018-11-23 5:37 ` Nicolas Boichat
2018-11-23 5:37 ` Nicolas Boichat
2018-11-23 5:37 ` Nicolas Boichat
2018-11-23 12:23 ` Vlastimil Babka
2018-11-23 12:23 ` Vlastimil Babka
2018-11-23 12:23 ` Vlastimil Babka
2018-11-23 12:30 ` Michal Hocko [this message]
2018-11-23 12:30 ` Michal Hocko
2018-11-23 12:30 ` Michal Hocko
2018-11-26 8:02 ` Christoph Hellwig
2018-11-26 8:02 ` Christoph Hellwig
2018-11-26 8:02 ` Christoph Hellwig
2018-11-28 8:55 ` Nicolas Boichat
2018-11-28 8:55 ` Nicolas Boichat
2018-11-28 8:55 ` Nicolas Boichat
2018-12-04 9:37 ` Nicolas Boichat
2018-12-04 9:37 ` Nicolas Boichat
2018-12-04 14:35 ` Vlastimil Babka
2018-12-04 14:35 ` Vlastimil Babka
2018-12-04 14:35 ` Vlastimil Babka
2018-12-05 2:04 ` Nicolas Boichat
2018-12-05 2:04 ` Nicolas Boichat
2018-12-05 2:04 ` Nicolas Boichat
2018-12-05 5:51 ` Nicolas Boichat
2018-12-05 5:51 ` Nicolas Boichat
2018-12-05 5:51 ` Nicolas Boichat
2018-12-05 14:41 ` Will Deacon
2018-12-05 14:41 ` Will Deacon
2018-12-05 14:41 ` Will Deacon
2018-12-04 16:28 ` Will Deacon
2018-12-04 16:28 ` Will Deacon
2018-12-04 16:28 ` Will Deacon
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